1. Field of the Invention
This invention pertains to building construction, and more particularly to apparatus for attaching insulation panels to structural substrates.
2. Description of the Prior Art
Many types of buildings include compressible insulation panels attached to structural substrates. The insulation panels are typically attached in place by mechanical fasteners such as screws or nails in conjunction with specialized attachment devices. The attachment devices are commonly thin plates having relatively large areas. The plates are placed on the insulation panel surface which is disposed opposite the surface of the panel which is disposed in contact with the substrate, and the fasteners are driven through the plates and insulation panel into the substrate.
The process of attaching insulation panels to buildings has traditionally been slow and costly. If screws are used as the fasteners, holes must be predrilled into the masonry or other substrate. Self-drilling screws require time for drilling and tapping. Further, the screws must be fed individually into the front of an electric screw gun tool. With powder driven nails as the fasteners, the nails and powder loads must be fed individually or in small numbers, usually by hand, into the power setting tool.
Examples of prior insulation panel attachment devices may be seen in U.S. Pat. Nos. 2,307,348; 4,380,413; 4,545,270; 4,606,168; and 4,862,664. The attachment devices of the foregoing patents do not pass completely through an insulation panel from its exposed surface to the substrate. Consequently, it is difficult to consistently apply the correct amount of force to the fasteners. If too little force is applied, the plate portions of the attachment devices will project improperly above the exposed surface of the insulation panel. In addition, the fasteners will not be sufficiently embedded into the substrate, so they will have a tendency to work loose. If too much force is applied to the attachment devices, they will penetrate excessively into the insulation panels.
U.S. Pat. Nos. 5,054,983 and 5,171,118 show insulation panel attachment devices that pass entirely through insulation panels. These attachment devices can thus clamp insulation panels to a substrate with a uniform force. On the other hand, these devices of the two patents suffer the drawback of being unable to accommodate insulation panels having thicknesses that vary from a nominal thickness. Further, the devices of the foregoing patents require installation by power setting tools that require individual feeding of the nails and the powder loads. Consequently, installation times are undesirably high.